The present invention generally relates to storage systems and, more particularly, to a system and method for optimizing performance of storage systems that include solid state drives (SSD) and magnetic hard disk drives (HDD).
Storage systems support SSDs that may provide various benefits over HDDs, such as faster data access and throughput, better performance, and less power consumption. SSDs are capable of reading and writing data much more quickly than HDDs. For example, SSDs may be capable of 500 or more I/O operations per second (IOPS), while HDDs may be capable of only 150 IOPS. Accordingly, by moving frequently accessed data extents to SSD storage, the performance of a storage system may be optimized.
SDDs may be more expensive than HDDs and therefore the total storage volume in a storage system may be provided by a mix of HDDs and SDDs. To optimize the performance of a storage system that includes both HDDs and SSDs, infrequently accessed data extents may be located on HDDs due to their lower cost and frequently accessed data extents may be located on SSDs due to their higher performance.
Systems may optimize storage system performance by relocating data extents after an extended evaluation period in order to optimize performance. The evaluation period used by optimizers is long and static. During this evaluation period, typically between two and 14 days elapse prior to the optimizer moving data extents between HDDs and SDDs.